Studies on vitro preparation of recombinant retrovirus, concentrate and storage

Recombinant retroviral vector(pLXSN) carrying NeoR were transfected into PA3 17 by lipofectin and calcium phosphate precipitation. The cell supernatants from G418- resistant PA317 in which there are recombinant retroviral were concentrated through centrifuge at different speeds at 4℃. The concen-trated viral supernatants were stored at- 80℃ for three months. NIH3T3 were infected to measure the titer of viral supernatants. The results showed there are no marked differences between the titer of concentrated viral supernatants and unconcentrated viral supernatants, the titer of concentrated viral supernatants stored at- 80℃ for three months can still attain 106 cfu/ml, and it has the ideal capacity of infecting target cell.